Safety shut-off and automatic control device for gaseous fuel burners



3 Sheets-Sheet l R. B. MATTHEWS SAFETY SHUT-OFF AND AUTOMATIC CONTROL DEVICE FOR GASEIOUS FUEL. BURNERS April 24, 1956 Filed May 5, 1954 INVENTOR. 526565! E. M 323% 6M6 BY limo), (9432A r0124; 2;

April 24, 1956 R. B. MATTHEWS SAFETY SHUT-OFF AND AUTOMATIC CONTROL DEVICE FOR GASEOUS FUEL. BURNERS 3 Sheets-Sheet 2 Filed May 5, 1954 INVENTOR. fiaisell .5. MQii/ZG April 24, 1956 Filed May 5, 1954 R. SAFETY SHUT-OF B. MATTHEWS F AND AUTOMATIC CONTROL DEVICE FOR GASEOUS FUEL BURNERS I5 Sheets-Sheet 5 Russell B. Matthews United States Patent SAFETY SHUT-OFF AND AUTOMATIC CONTROL DEVICE FOR GASEOUS FUEL BURNERS Russell B. Matthews, Wauwatosa, Wis., assignor to Milwaukee Gas Specialty Company, Milwaukee, Wis., a corporation of Wisconsin Application May 5, 1954, Serial No. 427,701 Claims. (Cl. 137--66) This application is a continuation-in-part of my application Serial No. 203,479, filed December 29, 1950, now abandoned, and relates, in general, to burner control devices, with particular relation to a safety' shut-off and automatic control device for gaseous fuel burners.

Thermoelectric safety shut-off devices for maintaining, for example, flow of fuel to a burner as long as a thermoelectric generator is heated by the flame of a pilot burner and for shutting off the flow of fuel to the burner upon extinguishment of the pilot burner flame are known in the art. Due to the inability of the minute thermoelectric current that can'be generated by the heat of a pilot burner flame on a thermoelectric generator to open the shut-off valve, it has been previously proposed to employ, for example, a diaphragm valve which operates in conjunction with the thermoelectric generator and its electromagnet to establish a flow of fuel to the burner upon energization of the electromagnet by the heat of the pilot burner flame on the thermoelectric generator.

These latter devices have been automatic or selfoperating, and are suitable for that purpose, but they are not deemed suitable for safety shut-off purposes. Leakage of fuel at such a diaphragm valve or at the bleed passage therefor may permit the valve to open or remain open while the pilot burner flame is extinguished. This would permit the escape of unburned gas from the main burner with possible serious consequences.

While in the particular embodiment of the invention selected for illustration a diaphragm valve is used in accomplishing the automatic control, it is to be understood that automatic control may be accomplished in other ways, for example by an electroresponsive valve, within the broader aspects of the present invention.

One of the main objects of the present invention is to provide an improved safety shut-off and automatic control device which will provide not only for automatic control of the flow of gaseous fuel for a burner but also a safety shut-off control.

Another object of the invention is to provide a safety shut-off and automatic control device which does not rely for the safety shut-off control on the valve for obtaining the automatic control and which, therefore, does not have the shortcomings and disadvantages which would be presented if a single valve were relied on for both the automatic control and the safety shut-off func tions.

Another object of the invention is to provide a control device for controlling the temperature, for example, at a remote location by means of a thermostat having contacts in series with an electromagnet and a thermoelectric generator located, for example, in a pilot burner flame for supplying the necessary power to the electromagnet to move an armature to attracted position to control the flow of fuel to a main burner in accordance with the demands of the temperature adjacent to the thermostat.

Another object of the invention is to provide an improved control device with which shut-oil of the fuel is obtained in case the pilot burner is extinguished.

Another object of the invention is to provide a control device having a fixed armature and a movable electromagnet for accomplishing the new and advantageous results set forth.

Another object of the invention is to provide a control device having in combination fixed and movable electromagnet frame and armature members which are held in attracted position relative to each other when the electromagnet is energized by the heat of a pilot burner flame on a thermoelectric generator, and wherein there is a movable second armature for obtaining the automatic control and which is actuated to and held in attracted position with respect to said fixed member by shunting of flux from the latter when additional magnetic flux is established in the magnet frame by a thermoelectric circuit under the control, for example, of a switch, thermostat, or other condition-responsive device, said additional flux affording more than enoughflux flow in said frame and armature to cause saturation of a portion of said fixed member and thereby causing shunting of flux from said portion.

Further objects and advantages, and numerous modifications and adaptations of the invention will appear from the following detailed description taken in connection with the accompanying drawings, in which:

Figures 1 and 2 are parts of a more or less diagrammatic view which, when placed with Figure 2 below Figure l and with the line AA of Figure l on the line BB of Figure 2, form a complete diagrammatic view of one illustrative system embodying the control device of the present invention which is shown partially broken away and in section in Figure l; and

Figure 3 is a more or less diagrammatic view, partly in vertical section, of another form of the invention.

Referring now to Figures 1 and 2 of the drawings, the particular form of safety shut-off and automatic control device selected for illustration therein comprises a valve body 1 having a fuel inlet 2 and a fuel outlet 3. The inlet 2 opens into an inlet chamber 4, and the outlet 3 opens from an outlet chamber 5. Between the chambers 4 and 5 there is a wall or partition 6 provided with an opening 7. An annular valve seat 8 surrounds the inlet end of the opening 7, and an annular valve seat 9 surrounds the outlet end of the opening 7. A pilot port or tapping 10 opens from the opening 7 between the valve seats 8 and 9 for supplying gaseous fuel to a pilot burner 11 through a pilot burner supply tube or pipe 12.

The pilot burner 11 is disposed in juxtaposition or in lighting proximity to a main burner 13. The burner 13 is supplied with gaseous fuel by a pipe 14, contiguous sections of which are connected to the inlet 2 and outlet 3, with the pipe section which is connected to the outlet 3 leading to the burner 13. The supply of fuel to the main burner 13 may be through a mixing chamber 15 to which air is admitted, as well understood in the art.

Fixed to the valve body nut 16 is a hood l7 closed 18. An armature 19 is mounted in fixed position within the hood 17. A stem 20 extends for axial movement through an opening in the wall 18 at the inner end of the hood 17. If desired the opening through which the stem 20 extends may be suitably packed at 21 to prevent leakage of gas into the hood 17. The magnet frame 22 of an electromagnet, indicated in its entirety at 23, is attached to one end of the stem 20 within the hood 17. A safety shut-off valve 24 is attached to the opposite end of the stem 20 within the inlet chamber 4.

The electromagnet 23 has one position with the pole 1, for example, by a flange at its inner end by a wall ends of the magnet frame 22 in attracted relation to the armature 19 as shown in Figure 1, and another position in which the magnet frame is retracted from the armature '19. When the electromagnet 23 is in attracted po sition, the valve 24 is held open as shown in Figure 1, and when the electromagnet 23 is retracted, the valve 24 seats against the valve seat 8 and shuts off the flow of gaseous fuel-to the main burner 13; also the flow of fuel to the pilot burner 11. The attachment of the valve 24 to the stem may be in a manner to permit self-accommodation of the valve 24 to its valve seat 8. The attachment of the electromagnet 23 to the stem 20 may be in a manner to permit self-accommodation of the pole ends of the magnet frame 22 to the armature 19.

A coil 26 is wound, for example, around one of the legs of the magnet frame 22 which is shown of U-shaped form, and is connected in circuit with a thermoelectric generator 27 by a lead 28. The lead 28 may, for example, comprise concentric lead conductors 29 and 30 connected in circuit at one end with concentric thermoelectric elements 31 and 32 of the thermoelectric generator 27 as more fully disclosed and claimed in Oscar I. Leins Patent No. 2,126,564, patented August 9, 1938. The thermoelectric elements 31 and 32 are joined to form a hot thermojunction 34 which, in use, is positioned to be heated by the flame of the pilot burner 11. The opposite ends of the outer tubular and inner lead conductors 29 and 30 are connected to the terminals of the coil 26, for ex ample, by a detachable terminal connector 35.

A second coil 38 is wound, for example, around the other leg of the magnet frame 22. One terminal of the coil 38 is connected, for example, with the fixed contact 39 of a thermostat 49 by a conductor 41. The other terminal of the coil 38 is connected by a conductor 42 with one of the thermoelectric elements 43 of a thermoelectric generator 44. The other thermoelectric element 45 of the second thermoelectric generator 44 is connected by a conductor 46 with the other or movable terminal 47 of the thermostat 40. The thermoelectric elements 43 and 44 are joined to form a hot thermojunction 48 which, in use, is positioned to be heated by the flame of the pilot burn-- er 11.

The thermoelectric generator 44 and its leads 42 and 46 may be of concentric form, as more fully disclosed and claimed in the previously identified Oscar J. Leins patent. While the thermoelectric generators 27 and 44 are shown and described as thermocouples, it is to be understood that thermopiles may be used as and where suitable or desired.

The heat of the flame of the pilot burner 11 on the thermoelectric generator 2'7 is adapted to energize the electromagnet 23 sufiiciently to hold it attracted to the armature 19 and the valve 24 in open position as long as the thermoelectric generator 27 is heated by the flame of the pilot burner 11. When the flame of the pilot burner 11 is extinguished, the electromagnet 23 ceases to be held attracted to the armature 19. The electromagnet 23 is then moved to retracted position with accompanying movement of the valve 24 to closed or shut-off position by a coiled spring 50. The spring 50 is confined, for example, between the valve 24 and the wall 18.

Within the broader aspects of the present invention, 1 contemplate using in place of the valve 24 a switch or other controlling member which will have operating position when the electromagnet 23 is in attracted position, and inoperative or safety shut-off position when the electromagnet 23 is retracted.

The heat of the flame of the pilot burner 11 on the hot junction or hot junctions of the thermoelectric generator 27 may not be capable of moving the electromagnet 23 to attracted position and the valve 24 to open position. Reset means is, therefore, provided for resetting or cocking the electromagnet 23 to attracted position and the valve 24 to open position. This reset means comprises, in general, a reset stem 52 mounted for axial 'stem 52 is provided with a reset button movement in the valve body 1. The outer end of the S3. A coiled spring 54 holds the reset stem 52 in its outwardly projected position, and returns it to such position.

hen the electromagnet 23 is retracted and the valve member 24 is closed and the reset stern 52 is pressed inwardly, the inner end of the stem engages the valve and electromagnet assembly and moves the valve member 24 to open position and the electromagnet 23 to attracted position, with the pole ends of the magnet frame 22 against the armature 19. They may be held in this position until the pilot burner 11 is ignited and the flame thereof has heated the hot junction of the thermoelectric generator 27 sufficiently to hold the electromagnet 23 in attracted position and the valve 24 in open position, whereupon the reset stem 52 may be released and will be returned spring 54.

if desired, the reset stem 52 may be provided with a flow interrupter valve 56 for seating against the valve seat 9 to shut oif the flow of fuel to the main burner 13 during the resetting operation and until the electromagnet 23 is held in attracted position with the valve member 24 in open position by the energization of the electromagnet 23 and the reset stem 52 is released. The fiow interrupter valve may, for example, be of the character more fully disclosed and claimed in Charles V. Hildebrecht Patent No. 2,114,446, patented April 19, 1938. Suflice it to state that when the reset stem 52 is pressed inwardly, a coiled spring 58 moves the flow interrupter valve 56 to closed position against its seat 9, and the coiled spring 54, in returning the reset stem 52 to its outwardly projected position, moves the valve member 56 to open position against the action of the spring 58.

During the time that the flow interrupter valve 56 is seated against its seat 9, the fiow of gaseous fuel to the main burner is shut off, but the valve 24, being open, fuel may flow through the pilot port 10 and tube 12 to the pilot burner 11.

The safety shut-off and automatic control device also has a second armature 60 which is movable from retracted position to attracted position relative to the first an'nature 19, and vice versa. With the control device arranged in upright position and the armature 60 positioned beneath the armature 19, the armature 60 may drop by gravity to its retracted position and be actuated to attracted position as will presently appear. It is to be understood, however, that the armature 60 may be actuated to retracted position, for example, by a relatively weak coiled spring interposed between the armatures 19 and 60. This will permit the use of the control device in positions in which the armature 60 would not move by gravity to retracted position.

When the coil 26 is energized by its thermoelectric generator 27, with the magnet frame 22 in attracted position, magnetic flux is established in the magnet frame 22, which flux links the armature 19 and holds the electromagnet 23 v in attracted position with the magnet frame 22 against the armature 19.

When the second coil 38 is energized by its thermoelectric generator 44, it produces additional magnetic fiux in the magnet frame 22, assuming that the coil 26 is energized and that the magnet frame 22 is in attracted position against the first armature 19. The coils 26 and 38 and the magnet frame 22 and armature 19 are so designed that the operating flux density produced by the energization of both coils 26 and 38 is just above that required to saturate the armature 19.

To the foregoing end, the armature 19 is shown as having in its lower surface a diametrical slot or saw-cut 62. This slot or saw cut 62 presents across the magnetic flux path in the armature 19 a reluctance which, when the electromagnet 23 is in attracted position and both coils 26 and 38 are energized, is sufficient to divert through the second armature 60 at least sufficient of the to its outwardly projected position by the additional or greater amount of magnetic flux established by energization of the coil 38 when the coil 26 is also energized. This linking of the armature 60 by the greater or additional flux actuates the armature 60 to attracted position relative to the armature 19, and retains the armature 60 in attracted position.

The splitting of the first armature 19 by the slot or saw-cut 62 not only achieves saturation of the armature 19 by the additional magnetic flux, but also creates two new pole faces which cooperate with the secondary armature 60. This provides for utilizing the leakage flux more efficiently.

In the device of the present invention, the operation of the secondary armature 60 is utilized to provide automatic control of the flow of fuel to the main burner 13. This is accomplished, for example, by interposing in the fuel supply pipe 14 leading to the main burner 13, and preferably between the safety shut-off and automatic control device and the main burner, a diaphragm type valve 65.

The diaphragm valve 65 selected for illustration is, in general, of the type more fully shown and described in Guido Wunsch and Josef Schuppert Patent No. 2,291,567, patented July 28, 1942.

Suffice it for purposes of the present application to state that the valve 65 comprises a valve body 70 having a fuel inlet 71 and a fuel outlet 72 connected to contiguous sections of the pipe 14, with the pipe section 14 con,- nected to the outlet 72 leading to the main burner 13. Between the inlet 71 and the outlet 72 the valve body 70 has a port or valve opening 73 which is adapted to be closed by a valve 74. The valve 74 is carried by a flexible diaphragm 75 which separates the fuel inlet and outlet side of the valve from a chamber 76.

An orifice or tube 78 bleeds gas, for example, from the inlet 71 into the chamber 76. A tube 79 leads from the chamber 76, for example, into a chamber 80 formed in the bottom of the hood l7 beneath the first or primary armature 19. Another tube 81 leads from the chamber 80, for example, to position at 82 adjacent to the pilot burner 11. The upper ends of the tubes 79 and 81 are presented toward the movable secondary armature 60 so that when this armature drops or otherwise moves to retracted position, it seats upon and closes the upper ends of the tubes 79 and 81.

The sizes of the orifices the tubes 78 and 79 are so proportioned that when ports 84 and 85 at the upper ends of the tubes 79 and 81 are uncovered, gas bleeds out tube 79 fastervthan it enters the chamber 76 through the tube 78. This reduces the pressure on the top of the diaphragm 75 and permits'the fuel pressure on the bottom of the diaphragm from the inlet 71 to move the diaphragm 75 upwardly and thereby the valve 74 to open position. If the safety shut-off valve is open, this allows gas to flow to the main burner where it is ignited by the pilot burner.

The operation of the embodiment of the invention illustrated in Figures 1 and 2 is as follows:

Depressing the reset button 53 forces the magnet frame 22 of the electromagnet 23 against the fixed armature 19, and opens the valve 24. This admits gas to the pilot burner 11 which, when ignited heats the thermoelectric generators 27 and 44. The voltage generated by the thermoelectric generator 27 causes thermoelectric current to flow through the conductors 29 the coil 26 which, by virtue of its magnetic field, holds the magnet 22 against the armature 19. Release of the reset button 53 results in movement of the flow interrupter valve 56 to open position and allows the flow of fuel through the pipe 14 to the diaphragm valve.

If the thermostat 40 is calling for heat, the contacts 47 and 39 are in engagement completing the electrical circuit from the thermoelectric generator 44 through the conductors 42 and 46 and the coil 38. -Magnetic flux generated by the auxiliary coil 38 links the armature 60,

and 30 and through or passageways provided by causing it to lift up against the lower side of the armature 19. The movement of the auxiliary armature 60 to attracted position opens the orifices 84 and 85. This permits gas to bleed off from the top of the diaphragm 75 (i. e., from the chamber 76) through the bleed tubes 79 and 81 t0 the flame at the pilot burner 11 where it is ignited. The bleeding of gas out from the chamber 76 is faster than it enters through the tube 78 and reduces the pressure on the top of the diaphragm 75, and the fuel pressure at the inlet 71 lifts the valve 74 to open position.

Opening of the valve 74 allows gas to pass to the main burner 13 which is ignited by the pilot burner 11, and raises the ambient temperature surrounding the thermostat 40. This increase in temperature surrounding the thermostat 40 causes contact 47 to separate from contact 39. This opens the circuit for the auxiliary coil 38 and thereby deenergizes this coil. As a result, the armature 60 drops or moves to retracted position and seals off the ports 84 and 85. This causes pressure within the chamber 76 on top of the diaphragm 75 to build up and move the valve 74 to closed position, shutting off the supply of fuel to the main burner.

From the foregoing it will be apparent that the auxiliary armature operates in conjunction with its related parts to provide automatic control of the supply of fuel for the main burner. The movable electromagnet with the main armature 19 and their related parts provide a safety shut-off control which shuts ofl 100% the flow of fuel to both the main burner and the pilot burner upon extinguishment of the flame of the pilot burner and irrespective of whether the valve 74 is open or closed.

In Figure 3, which illustrates another form of the invention, the parts indicated by primed numerals correspond to similar parts in Figures 1 and 2 indicated by the same numerals unprirned. In the form of the invention shown in Figure 3, the valve body 1' is flared at its lower end and provides a cover for the diaphragm valve body the diaphragm being marginally clamped between said valve body and cover. The valve body 1' may be cylindrical in shape, and fixed within its lower end is a cylindrical plug 91 having a cylindrical recess formed in its upper surface. A magnetically permeable auxiliary armature disc 60 is positioned within the recess 80 and has a diameter substantially smaller than that of the recess T he plug 91 is formed with a passage 79' affording communication between a marginal portion of the recess 80 and the chamber 76' above the diaphragm 75'. The plug 91 is also formed with a passage 89 which affords communication between a port disposed centrally of the bottom surface of the recess 80 and a vent conduit 81.

Fixed within the valve body 1 above the plug 91 is an electromagnet 23 having a magnetically permeable frame comprising a cylindrical plug or disc 92 formed with a pair of spaced upstanding pole pieces 22'. The disc portion 92 of the electromagnet frame is formed on its undersurface with a diametrically extending slot or groove 62' which substantially reduces the thickness of said disc portion adjacent said groove. The disc portion 92 is also formed with a passage 88 affording communication between a port in the undersurface of said disc above the auxiliary armature 60 and a fuel inlet conduit 78' which branches from the fuel supply pipe 14' as shown.

Energizing coils 26 and 38' are each wound around a separate pole piece 22as shown. The coil 26' is connected in circuit with the terminals of a thermoelectric genjerator 27 by means of conductors 29 and 30'. A conductor 42' connects one terminal of the coil 38' in circuit with the conductor 29, and a conductor 46 connects the other terminal of the coil 38' with one of the terminals of a thermostat 40'. A conductor 41 connects the other terminal of the thermostat 40' in circuit with the conductor 30'. It is apparent, therefore, that the coils 26' and 38' are in parallel circuit relationship with the thermoelectric generator 27, and that energization of the coil 38 is under the control of the thermostat 40 connected in series circuit therewith.

The operation of the embodiment of the invention illustrated in Figure 3 is as follows:

Depressing the reset button 53 forces the armature 19' against the pole faces of the pole pieces 22 of the electromagnet 23, and opens the valve 24. This permits gas fiow through the conduit 12 to the pilot burner 11' which, when ignited, heats the thermoelectric generator 27 The voltage generated by the thermoelectric generator 27' causes thermoelectric current to flow through the conductors 29' and 30 and through the coil 26 which generates sufiicient flux flow through the electromagnet frame and the armature 19 to hold said armature attracted to the pole faces of the electromagnet 23. Release of the reset button 53 results in movement of the fiow interrupter valve 56' to open position and allows the fiow of fuel through the pipe 14' to the diaphragm valve.

If the thermostat 41) is calling for heat, the contacts thereof are in engagement, completing the electrical circuit from the thermoelectric generator 27 to the coil 38' through the conductors 29, 30, 41', 42 and 46. Magnetic flux generated by the auxiliary coil 38' links the armature 69, causing it to lift up against the undersurface of the electromagnet frame portion 92 closingoff the port 90 and uncovering the port 35. This permits gas to bleed off from the top of the diaphragm 75' (i. e., from the chamber 76') through the passages 79' and 89, and the conduit 81, to the flame at the pilot burner 11 where it is ignited. The bleeding of gas out of the chamber 76' reduces the pressure on the top of the diaphragm 75, and the fuel pressure on the underside of said diaphragm lifts the valve 74 to open position.

Opening of the valve 74 allows gas to pass to the main burner 13 where it is ignited by the pilot burner 11' and raises the ambient temperature surrounding the thermostat 40' to cause the contacts thereof to separate. This opens the circuit for the auxiliary coil 38 and thereby deenergizes said coil. As a result, the armature 60' drops or moves to retracted position and thereby seals off the port 85 while uncovering the port 90. Pressure then builds up within the chamber 76' on top of the diaphragm 75 and the valve 7 4' moves to closed position, shutting off the supply of fuel to the main burner.

The provision of the diametrical slot or groove 62' in the electromagnet frame portion 92 reduces the thickness of said portion, adjacent said slot and thereby limits the amount of magnetic flux which can fiow through said portion to substantially that which affords saturation of said portion. Thus, when the armature 19 is in attracted position and both of the coils 26' and 38' are energized, the flux generated by both of said coils is more than sufiicient to saturate the portion of the 'electromagnet frame adjacent the slot 62' and as a result, flux is diverted'from said frame and linksthe auxiliary armature 60' to cause actuation thereof to attracted position against the lower surface of the frame portion 92. This diverted flux retains the armature 69 in attracted position as long as the auxiliary coil 38 is energized.

As in the form of the invention illustrated in Figures 1 and 2, the form of the invention illustrated in Figure 3 provides an auxiliary armature which operates in conjunction with its related parts to provide automatic control of the supply of fuel for the main burner. The movable main armature 19', valve 24' and the electromagnet 23' and their related parts provide a safety shut-off control which shuts off the flow of fuel to both the main burner and pilot burner on extinguishment of the flame of the pilot burner and irrespective of whether the valve 74' is open or closed, thus providing 100% shut-off.

The embodiment of the invention shown in the drawings is for illustrative purposes only, and it is to be expressly understood that said drawings and the accompanying specification are not to be construed as a definition of the limits or scope of the invention, reference being had to the 3P-. pended claims for that purpose.

I claim:

1. An electromagnetic control device, comprising: means defining a low reluctance flux path comprising first and second magnetic members relatively movable to attracted relation and biased to separated relation, means defining a fluid passage, a first main valve in said passage operatively. related to one of said magnetic members and movable to open and closed positions by movement of said magnetic members to said attracted and separated relations, means for establishing magnetic flux flow in said tiux path at two predetermined different density levels, said flux flow at the lower ofsaid density levels being sufiicient to hold said magnetic members in said attracted relation when moved thereto against said bias, whereas said flux flow at the higher of said density levels is above that required to saturate a portion of said flux path, whereby flux is shunted from said flux path, a magnetic control member positioned to be linked by said shunted flux and to be actuated thereby from a first to a second controlling position, and a second main valve in said fluid passage in series with said. first main valve and operatively related to said magneticicontrol member to be actuated to open and closed positions by movement of said second control member to its controlling positions.

2. An electromagnetic control device, comprising: means defining a lowreluctance flux path comprising first and second magnetic members relatively movable to attracted relation, means defining a fluid passage, and biased to separated relation, a first main valve in said passage operatively related to one of said magnetic members and movable to open and closed positions by move ment of said'magnetic members to said attracted and separated relations, means for establishing magnetic flux flow in said flux path at two predetermined different density levels, said flux fiow at the lower of said density levels being sufficient to hold said magnetic members in said attracted relation when moved thereto against said bias, whereas said fiux flow at the higher of said density levels is above that required to saturate a portion of said flux path, whereby flux is shunted from said flux path, a fiuidpressure operated second main valve in series with said first main valve in said fluid passage, and

pilot valve means operatively associated with said fluid pressure operated valve for controlling the latter, said pilot valve means comprising a movable magnetic member positioned to be linked by saidshunted flux and to be actuated thereby from a first to a second controlling position. 7 a

3. An electromagnetic control device, comprising: means including first and second magnetic members biased toward separated relation and relatively movable to attracted relation providing a low reluctance llux path, means tending to establish magnetic flux fiow through said flux path at a first level sufficient to hold said magnetic members in attracted relation when moved thereto against said bias and through the same path at a predetermined higher density level, said low reluctance flux path means including a portion having a crosshectional area of a size permitting fiux flow therethrough at said first density level and saturable by flux flow therethrough at less than said predetermined higher density level, wherefore on flux flow through said flux path means at said higher density level flux is shunted from said flux path adjacent said saturable portion, and a magnetic control member positioned to be linked by said shunted flux and to be actuated thereby from a first to a second controlling position. i

4. An electromagnetic control device, comprising: means includingelectromagnet frame and armature members biased toward separated relation and relatively movable to' attracted relation providing a low reluctance flux path, coil means'forsaid electromagnet frame member, thermoelectric generator means connected to energize said coil means and tending to establish magnetic flux flow through said flux path at a first level suflicient to hold said members in attra;ted relation when moved thereto against said bias and through the same path at a predetermined higher density level, said low reluctance flux path means including a portion having a crosssectional area of a size permitting flux fiow therethrough at said first density level and saturable by fiux flow therethrough at less than said predetermined higher density level, wherefore on flux flow through said flux path means at said higher density level flux is shunted from said fiux path adjacent said saturable portion, and a magnetic control member positioned to be linked by said shunted flux and to be actuated thereby from a first to a second controlling position.

5. An electromagnetic control device, comprising: means including first and second relatively movable magnetic members biased toward a retracted position and movable to an attracted position providing a low reluctance flux path, first flux generating means for establishing magnetic flux flow through said flux path at a first level suificient to hold said movable members in attracted position when moved thereto against said bias, second flux generating means operable with said first flux generating means to establish flux flow path at a predetermined higher density level, said flux path means having a portion having a cross-sectional area of a size permitting flux flow therethrough at said first density level and saturable by flux flow therethrough at less than said predetermined higher density level, wherefore on flux flow through said flux path at said higher density level fiux is shunted from said flux path adjacent said saturable portion, and a magnetic control member positioned to be linked by said shunted flux and to be actuated thereby from a first to a second controlling position.

6. An electromagnetic control device, comprising: means including relatively movable electromagnet frame and armature members biased toward a retracted position and movable to an attracted position providing a ow reluctance flux path, first and second energizing coils or said electromagnet frame member, thermoelectric generator means connected to energize said coils independently, energization of said first coil tending to establish magnetic flux flow through said electromagnet frame and armature members at a first level suflicient to hold said movable member in attracted position when moved thereto against said bias, and energization of said second coil while said first coil is energized affording additional magnetic flux in the same path and tending to establish flux flow through said path and through said members at a predetermined higher density level, said flux path means having a portion having a cross-sectional area of a size permitting flux flow therethrough at said first density level and saturable by flux flow therethrough at less than said predetermined higher density level, wherefore on flux flow through said flux path at said higher density level fiux is shunted from said flux path adjacent said saturable portion, and a magnetic control member positioned to be linked by said shunted flux and to be actuated thereby from a first to a second controlling position.

7. An electromagnetic control device, comprising: means including relatively movable electromagnet frame and armature members biased toward a retracted posi- .tion and movable to an attracted position providing a low reluctance flux path, first and second energizing coils for said electromagnet frame member, a thermoelectric generator connected to energize said coils independently, energization of said first coil tending to establish magnetic flux flow through said electromagnet frame and armature members at a first level suificient to hold said members in attracted position when moved thereto against said bias, first 'coil is energized aflording additional magnetic flux through the sameand energization of said second coil while said 10 in the same path and tending to establish fiux flow through said path and through said members at a predetermined higher density level, said low reluctance flux path means having a portion having a cross-sectional area of a size permitting flux flow therethrough at said first density level and saturable by flux flow therethrough at less than said predetermined higher density level, wherefore on fiux flow through said flux path at said higher density :level flux is shunted from said flux path adjacent said saturable portion, and a magnetic control member positioned to be linked by said shunted flux and to be actuated thereby from a first to a second controlling position.

8. An electromagnetic control device, comprising: means including a fixed magnetically permeable armature member and an electromagnet frame biased toward a retracted position separated from said armature member and movable to an attracted position in magnetic engagement with said armature member providing a low reluctance flux path, first and second energizing coils for said electromagnet frame member, thermoelectric generator means connected to energize said coils independently, energization of said first coil tending to establish magnetic flux flow through said electromagnet frame and armature members at a first level suflicient to hold said electromagnet frame in said attracted position when moved thereto against said bias, and energization of said second coil while said first coil is energized affording additional magnetic fiux in the same path and tending to establish flux flow through said path and through said members at a predetermined higher density level, said armature having a portion having a cross-sectional area of a size permitting flux flow therethrough at said first density level and saturable by flux flow therethrough at less than said predetermined higher density level, wherefore on flux flow through said path at said higher density level flux is shunted from said armature adjacent the saturable portion thereof, and a magnetic control member movable to attracted and retracted positions with respect to said armature and positioned to be linked by said shunted flux and to be actuated thereby from said retracted to said attracted position.

9. An electromagnetic control device, comprising: means including relatively movable electromagnet frame and armature members biased toward a retracted position and movable to an attracted position providing a low reluctance flux path, first and second energizing coils for said electromagnet frame member, a first thermoelectric generator connected to energize said first coil, a second thermoelectric generator connected independently to energize said second coil, energization of said first coil tending to establish magnetic flux flow through said electromagnet frame and armature members at a first level sufiicient to hold said members in said attracted position when moved thereto against said bias, and energization of said second coil while said first coil is energized affording additional magnetic flux in the same path and tending to establish flux fiow through said path and through said members at a predetermined higher density level, said flux path means having a portion having a cross-sectional area of a size permitting fiux flow therethrough at said first density level and saturable by flux flow therethrough -at less than said predetermined higher density level,

wherefore on flux flow through said path at said higher density level flux is shunted from said flux path adjacent said saturable portion, and a magnetic control member positioned to be linked by said shunted flux and to be actuated thereby from a first to a second controlling position.

10. An electromagnetic control device, comprising: means including a fixed magnetically permeable electromagnet frame member and a magnetically permeable armature member biased toward a retracted position separated from said frame member and movable to an attracted position in magnetic engagement with said frame fluid passage opening into said member providing a low reluctance flux path, first and second energizing coils for said electromagnet frame member, thermoelectric generator means connected to energize said coils independently, energization of said first coil tending to establish magnetic fiux flow through said electromagnet frame and armature members at a first level sufficient to hold said armature member in attracted position when moved thereto against said bias, and energization of said second coil while said first coil is energized affording additional magnetic flux in the same path and tending to establish flux flow through said path and through said members at a predetermined higher density level, said frame member having a portion having a crosssectional area of a size permitting flux flow therethrough at said first density level and saturable by flux flow therethrough at less than said predetermined higher density level, wherefore on fiux flow through said flux path at said higher density level flux is shunted from said frame member adjacent the saturable portion thereof, and a magnetic control member movable to attracted and retracted positions with respect to said frame member and positioned to be linked by said shunted flux and to be actuated thereby from said retracted to said attracted position.

. 11. An electromagnetic control device, comprising: means including first and second magnetic members one of which is fixed and is provided with a surface and with surface, and the other of which is movable, said movable member being biased toward a retracted position separated from said fixed member and being movable to an attracted position in magnetic engagement with said fixed member providing a low reluctance flux path, first fiux generating means for establishing magnetic flux flow through said flux path at a first level sufiicient to hold said movable member in attracted position when moved thereto against said bias, second flux generating means operable with said first flux generating means to establish flux flow through the same path at a predetermined higher density level, said fixed member having a portion having a cross-sectional area of a size permitting flux flow therethrough at said first density level and saturable by fiux flow therethrough at less than said predetermined higher density level, wherefore on flux flow through said fiux path at said higher density level flux is shunted from said fixed member adjacent the saturable portion thereof, and a magnetic control member movable to an attracted position with respect to said fixed member wherein it closes off said fluid passage and to a retracted position with respect to said fixed member wherein said passage is uncovered, said control member being positioned to be linked by said shunted flux and to be actuated thereby from said retracted to said attracted position.

12. An electromagnetic control device, comprising: means including first and second magnetic members biased toward separated relation and relatively movable to attracted relation providing a low reluctance flux path, a first control member operatively related to one of said magnetic members and movable to controlling positions by movement of said magnetic members to said attracted and separated relations, means tending to establish magnetic flux flow through said flux path at a first level sufficient to hold said magnetic members in attracted relation when moved thereto against said bias and through the same path at a predetermined higher density level, said low reluctance flux path means including a portion having a cross-sectional area of a size permitting flux flow therethrough at said first density level and saturable by fiux flow therethrough at less than said predetermined higher density level, wherefore on flux fiow through said flux path means at said higher density level flux is shunted from said flux path adjacent said saturable portion, and a magnetic second control member positioned to be linked by said shunted flux and to be actuated thereby from a first to a second controlling position.

13. An electromagnetic control device, comprising: means including relatively movable first and second magnetic members biased toward separated relation and movable to an attracted relation providing a low reluctance flux path, a first control member operatively related to one of said magnetic members and movable to controlling positions by relative movement of said members to said attracted and separated relations, first flux generating means for establishing magnetic flux flow through said flux path at a first level sufficient to hold said magnetic members in attracted relation when moved thereto against said bias, second flux generating means operable with said first flux generating means to establish flux flow through the same path at a predetermined higher density level, said fiux path means having a portion having a cross-sectional area of a size permitting flux flow therethrough at said first density level and saturable by flux flow therethrough at less than said predetermined higher density level, wherefore on flux flow through said fiux path at said higher density level flux is shunted from said fiux path adjacent said saturable portion, and a magnetic second control member positioned to be linked by said shunted flux and to be actuated thereby from a first to a second controlling position.

14. An electromagnetic control device, comprising: means including a fixed electromagnet frame member and a movable armature member biased toward a retracted position separated from said frame member and movable to an attracted position in magnetic engagement with said frame member providing a low reluctance flux path, a first control member operatively related to said armature and movable to controlling positions by movement of said armature to said attracted and retracted positions, first flux generating means for establishing magnetic flux flow through said flux path at a first level sufficient to hold said electromagnet frame in attracted position when moved thereto against said bias, second fiux generating means operable with said said first flux generating means to establish flux flow through the same flux path at a predetermined higher density level, said frame member having a portion having a cross-sectional area of a size permitting flux flow therethrough at said first density level and saturable by flux flow therethrough at less than said predetermined higher density level, wherefore on flux flow through said flux path at said higher density level fiux is shunted from said frame member adjacent the saturable portion thereof, and a magnetic second control member movable to attracted and retracted positions with respect to said frame member and positioned to be linked by said shunted flux and to be actuated thereby from said retracted to said attracted position.

15. An electromagnetic control device, comprising: means including a fixed magnetically permeable armature member and an electromagnet frame biased toward a retracted position separated from said armature member and movable to an attracted position in magnetic engagement with said armature member providing a low reluctance flux path, a first control member operatively related to said electromagnet frame and movable to controlling positions by movement of said eletromagnet frame to said attracted and retracted positions, first flux generating means for establishing magnetic flux flow through said fiux path at a first level sufiicient to hold said electromagnet frame in attracted position when moved thereto against said bias, second flux generating means operable with said first flux generating means to establish flux flow through the same path at a predetermined higher density level, said armature having a portion having a cross-sectional area of a size permitting flux flow therethrough at said first density level and saturable by flux flow therethrough at less than said predetermined higher density level, wherefore on flux fiow through said flux path at said higher density level flux is shunted from said armature adjacent the saturable portion thereof, and a magnetic second control member movable to attracted and retracted positions with respect to said armature and positioned to be linked by said shunted flux and to be actuated thereby from said retracted to said attracted position. v

16. An electromagnetic control device, comprising: means including electromagnet frame and armature members one of which is fixed and is provided with a surface and with fluid passage opening into said surface, and the other of which is movable, said movable member being biased toward a retracted position separated from said fixed member aind being movable to an attracted position in magnetic engagement with said fixed member providing a low reluctance flux path, a main valve connected to said movable member for movement to open and closed positions with movement of said movable member to attracted and retracted positions, first and second energizing coils for said electromagnet frame member, thermoelectric generator means connected to energize said coils independently, energization of said first coil tending to establish magnetic flux flow through said electromagnet frame and armature members at a first level sufficient to hold said movable member in attracted position when moved thereto against said bias, and energization of said second coil while said first coil is energized atfording additional magnetic flux in the same path and tending to establish flux flow through said path and through said members at a predetermined higher density level, said fixed member having a portion having a cross-sectional area of a size permitting flux flow therethrough at said first density level and saturable by flux flow therethrough at less than said predetermined higher density level, wherefore on flux flow through said flux path at said higher density level flux is shunted from said fixed member adjacent the saturable portion thereof, and a magnetic control member movable to an attracted position with respect to said fixed member wherein it closes otf said fluid passage and to a retracted position with respect to said fixed member wherein said passage is uncovered, said control member being positioned to be linked by said shunted flux and to be actuated thereby from said retracted to said attracted position.

17. An electromagnetic control device, comprising: means including first and second magnetic members biased toward separated relation and relatively movable to attracted relation providing a low reluctance flux path, a first control member operatively related to one of said magnetic members and movable to controlling positions by movement of said magnetic members to said attracted and separated relations, first fiux generating means for establishing magnetic flux flow through said flux path at a first level sufficient to hold said magnetic members in attracted relation when moved thereto against said bias, second flux generating means operable with said first flux generating means to establish flux flow through the same path at a predetermined higher density level, said low reluctance flux path means including a portion having a cross-sectional area of a size permitting flux flow therethrough at said first density level and saturable by flux flow therethrough at less than said predetermined higher density level, wherefore on flux flow through said fiux path means at said higher density level flux is shunted from said flux path adjacent said saturable portion, a magnetic second control member positioned to be linked by said shunted flux and to be actuated thereby from a first to a second controlling position, and a third control member operatively related to said second control member and movable to controlling positions by movement of said second control member to its controlling positions.

18. An electromagnetic control device, comprising: means including relatively movable first and second magnetic members biased toward separated relation and movable to attracted relation providing a low reluctance 14 r flux path, first flux generating means for establishing mag netic flux flow through said flux path at a first level sufficient to hold said magnetic members in said attracted relation when moved thereto against said bias, second flux generating means operable with said first flux generatingmeans to establish magnetic fiux fiow in the same path at a predetermined higher density level, said flux path means having a portion having a cross-sectional area of a size permitting flux flow therethrough at said first density level and saturable by flux flow therethrough at less than said predetermined higher density level, wherefore on flux flow through said path at said higher density level flux is shunted from said fiux path adjacent said saturable portion, a magnetic control member positioned to be linked by said shunted flux and to be actuated thereby from a first to a second controlling position, means defining a fluid passage, a first main valve in said passage operatively associated with one of said magnetic members for movement to open and closed positions with movement of said members to attracted and retracted relations, a fluid pressure operated main valve in said passage in series with said first main valve, said second valve having a chamber supplied with fluid under pressure and having vent passage means for said chamber positioned to be opened and closed by movement of said control member to its controlling positions.

19. An electromagnetic control device, comprising: means including first and second magnetic members biased toward separated relation and relatively movable to attracted relation providing a low reluctance flux path, means for effecting relative movement of said magnetic members to attracted relation and for holding said members in said relation against said bias, said means including first flux generating means for establishing magnetic flux flow through said flux path at a first level sutficient to hold said magnetic members in attracted relation when moved thereto against said bias, second flux generating means operable with said first flux generating means to establish flux flow through the same path at a predetermined higher density level, said low reluctance flux path means including a portion having a cross-sectional area of a size permitting flux flow therethrough at said first density level and saturable by flux flow therethrough at less than said predetermined higher density level, wherefore on flux flow through said flux path means at said higher density level flux is shunted from said flux path adjacent said saturable portion, and a magnetic control member positioned to be linked by said shunted Hurt and to be actuated thereby from a first to a second coritrolling position.

20. An electromagnetic control device, comprising: means including first and second magnetic members biased toward separated relation and relatively movable to attracted relation providing a low reluctance flux path, means for etfecting relative movement of said magnetic members to said attracted position against said bias, first flux generating means for establishing magnetic flux flow through said flux path at a first level sufiicient to hold said magnetic members in attracted relation when moved thereto against said bias, second flux generating means operable with said first flux generating means to establish flux flow through the same path at a predetermined higher density level, said low reluctance flux path means including a portion having a cross-sectional area of a size permitting flux flow therethrough at said first density level and saturable by flux flow therethrough at less than said predetermined higher density level, wherefore on flux flow through said flux path means at said higher density level flux is shunted from said fiux path adjacent said saturable portion, and a magnetic control member positioned to be linked by said shunted flux and to be actuated thereby from a first to a second controlling position.

(References on following page) References Cited in the file of this patent UNITED STATES PATENTS Veeder Oct. 28, 1890 Kronmiller June 21, 1938 5 Fillo Dec. 16, 1941 Ray Ian. 6, 1942 16 Ray Aug. 11, 1942 Alfrey Sept. 22, 1942 Ray Nov. 10, 1942 Alfrey May 4, 1943 Engholdt Mar. 27, 1945 Jackson Nov. 10, 1953 

